Compilare: user.cpp: In function ‘int main()’: user.cpp:87:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(last != v1[i].val) ^ user.cpp:107:50: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘long long int’ [-Wformat=] fprintf(fout, "%d", secventa5(u) - secventa5(l-1)); ^ user.cpp: In function ‘char nextch()’: user.cpp:15:58: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(pos==BUF_SIZE) fread(buf, BUF_SIZE, 1, fin), pos=0; ^